A display driver configured to drive a display panel such as a liquid crystal display panel and an OLED (organic light emitting diode) display panel may incorporate a memory configured to temporarily store image data therein. When a display panel is adapted to touch sensing, the memory may allow acquiring time sufficient for completing touch sensing.
Since a memory tends to occupy a large circuit size, a display driver may be designed to reduce the capacity of a memory integrated therein. Accordingly, a display driver may incorporate a memory having a capacity that is insufficient for storing image data associated with all the lines of an image displayed in each frame. When the number of lines of the image displayed in each frame, that is, the vertical resolution of the image is M, a display driver may incorporate a memory having a capacity for storing image data of only N lines, more specifically, a memory including N line memories or N memory regions each storing an image data of one line, where N<M. In this case, the N memory regions may be cyclically used in a wraparound manner to temporarily store image data therein corresponding to an image displayed in each frame (see JP 2014-203102 A).